Method of producing oil-soluble phthalic acid, polybasic aliphatic acid resin



Patented May 3, 1938 UNITED STATES METHOD OF PRODUCING OIL-SOLUBLEPHTHALIC ACID, POLYBASIO ALIPHATIC ACID RESIN Israel Bosenblum, NewYork, N. Y.

No Drawing. Application June 7, 1935, Serial No. 25,378

acid, one or more of the high molecular weight fatty acids obtainable byhydrolysis of a fatty triglyceride, particularly the fatty oils andfats, and a polybasic aliphatic acid or acids, particularly the morecommon and less expensive succinic, malic, and fumaric acids in suchproportions and undersuch conditions that fusible, oilsoluble resinousmixed esters of the polyhydric alcohol are obtained. s

I have found that by incorporating the polybasic acid in a fattytriglyceride acid-modified glycerol phthalate resin, valuable andunexpected advantages are secured. Thus, by chemically combiningsuccinic acid in a glycerol-phthalic acid-fatty acid resin a product isobtained which has an unusual degree of flexibility combined withsatisfactory adhesion, color retention and water and weather-resistance.

As pointed out in my copending application, Ser. No. 702,366 (Patent No.2,004,880) although reference is frequently made in the patentliterature to the effect that maleic acid can be substituted forphthalic acid in the production of a fatty oil acid modified alkydresin, I have found that this is not at all the case. Attempts by me andby others to my knowledge to replace the phthalic acid with maleic acid,that is, by reacting glycerol, maleic acid, and the acids of a fattyoil, have invariably resulted in the formation of two or morenon-compatible materials, one of which appears to be the condensate ofthe glycerol and the maleic acid, and further heating, no matter howcarefully, in the attempt to secure a homogeneous product resultedfinally only in the charring of the lower layer.

As set forth in the above mentioned patent, maleic acid is not theequivalent of phthalic acid when the reaction involves the presence alsoof the acids of a fatty oil or fat; and that in a reaction involving thesimultaneous heating of glycerol, maleic acid and fatty oil acids (thelastnamed' acids being present in an amount sufficient to make theproduct oil-soluble), such an amount of phthalic acid must likewise bepresent, that the molecular proportion of maleic to phthalic acid is nomore than approximately 1: 1. Any con-.

siderably greater proportion of maleic acid will result in the formationof a non-homogeneous, useless mixture. Thus, while maleic and phthalicacids are full equivalents in the binary reaction system composed ofglycerol and phthalic acid (which yields a resin insoluble in fattyoils), they are not fullequivalents in the ternary systemglycerol-phthalic acid-fatty oil acid which yields an oil-soluble resin.

I have found that succinic, niche and fumaric acids likewise are not theequivalent of phthalic acid in a reaction system involving glycerol,

phthalic acid and fatty oil acids and that, as in the case of maleicacid, the maximmn molecular proportion of, for example, succinic tophthalic acid is approximately 1: 1. This limiting proportion appliesnot only when all of the reacting materials are heated simultaneouslyfrom the beginning, but also when the glycerol is first heated with oneor both of the polybasic acids, and subsequently with the fatty oilacids, or is first partially reacted with the fatty oil acids and one ofthe polybasic acids and subsequently reacted with the other polybasicacid. Where, however, the glycerol is heated with a polybasic acid inthe absence of the fatty oil acid, the reaction must not be permitted togo to completion; and the fatty oil acids must be added while thecondensate of the glycerol and the polybasic acids is still plastic. Insuch case, of course, there are still free glycerol and polybasic acidpresent when the fatty oil acids are added, so that when the mixture isnow heated, a reaction occurs between all of the materialssimultaneously. This multi-step reaction applies not only to succinic,malic and fumaric acids, but also to maleic acid. In other words, wherethe glycerol is first heated with, for example, the phthalic andpolybasic aliphatic acids, or with the phthalic acid alone, or with thepolybasic aliphatic acid alone, followed by the addition of-the otherconstituents, the initial reaction must be of an incomplete character sothat when the last step of the process is conducted, free glycerol,phthalic acid, polybasic aliphatic acid and fatty oil acids are presentsimultaneously. These seemingly multi-stage processes are thus in factonly single stage processes, or at most only partially multi-stage, andare accordingly to be regarded as equivalent to the true single-stagereaction.

As described in my patent referred to above the use of maleic acid inconjunction with phthalic acid yields a material of especially palecolor, good color retention and body, the desired viscosity beingobtained in a very much shorter period of time than in the absence ofthe maleic acid. I have found that by using maleic acid simultaneouslywith succinic acid, the advantages of the maleic acid are combined withthose of succinic acid, namely, a high degree of flexibility.

The present application is a continuation in part of my copendingapplication, Ser. No. 506,298,"-filed Jan. 2, 1931, which has issuedasPatent No. 2,081,154, dated .May 25, 1937.

The invention will be further described in greater detail with the aidof the following examples which show by way of illustration severalmethods of carrying out the invention.

Example 1 Mols Grams Linoleic fatty acids 1 280 Phthalic anhydride 1 148Succinic anhydride 0.15 15 Glycerol 1.25 115 This mixture, in which thesuccinic anhydride is about 10% by weight of the phthalic anhydride andabout 9% of excess glycerol over the equivalent proportion theoreticallyrequired for complete neutralization is employed, is heated gradually toabout 230 C. and kept at that temperature until the desired low acidnumber and the desired viscosity are obtained. The material is a clearplastic, soluble in all common varnish solvents, and the solutions aremiscible with varnish oils, varnishes and resin solutions. The solutionsof the plastic can be used by themselves or mixture with others ascoatings and as vehicles for enamels, paints, etc. The coatings arepale, durable and of remarkable flexibility, elasticity and adhesion.They can be used for air-drying as well as baking finishes. Theoperation is carried out preferably in a neutral atmosphere.

Example 2 Mols Grams Linoleic fatty acids 1 280 Phthalic anhydride '74Succinic anhydride 50 Glycerol 1.1 101 Example 3 Mols Grams Linoleicfatty acids 1 280 Phthalic anhydride /2 74 Succinic anhydride 25 Maleicanhydride A; 24 Glycerol 1.1 101 The operation is conducted as inExample No. 1. The reaction proceeds rapidly and is completed inconsiderably shorter time than in Example 1. A resin of the samecommercial viscosity and low acid number is obtained, giving in solutionvery hard and elastic coatings of outstanding paleness.

Example 4 Mols Grams Linoleic fatty acid 1 280 Phthalic anhydride 0.5 74Succinic anhydride 0.15 15 Glycerine 1.3 120 are heated gradually toabout 200 C. for a short time until a uniform system without layers isobtained. There are then added:

Mols Grams Phthalic anhydride 0.5 74 Maleic anhydride 0.082 8 and thereaction continued at about 280 C. until a uniform, resinous product isobtained. In

this example the succinic anhydride is about 10% by weight of thephthalic anhydride and the maleic anhydride is 5%. The operation isperformed in two steps, leading in the end to a resin of the samegeneral characteristics as in Example 3.

Example 5 When it is attempted to produce the oil acid modifiedoil-soluble alkyd resin, containing d1- basic aliphatic acid, in twosteps, by first reacting the glycerol with the dibasic acids until aresinous intermediate product is obtained, followed by heating with theoil acid, a non-homogeneous useless product will be obtained unless, inaccordance with the present invention, the amount of dibasic aliphaticacid is kept low. Where the molecular proportion of dibasic aliphaticacid to phthalic acid is approximately 1:1, the glycerol must not beheated with the dibasic acids to the point where a resinous condensateis obtained but may be heated to only a very limited extent; in fact, toonly so small a degree that most of the glycerine and the acids are freewhen the fatty oil acids are added so that in effect the process reallyinvolves a single step. Thus when the following mixture Mols GramsPhthalic anhydride 0.5 74 Succinic anhydride 0.5 50 Glycerol 1.1 101 isheated prior to the addition of the fatty oil acid, great precautionsmust be taken to avoid any considerable degree of reaction.

The heating may be conducted to the point where the mixture is uniformand gives a clear mass when placed on glass. Thus the 'mixture may bequickly heated to about 140 C. and there are then immediately added 280grams (1 mol.) of linoleic (linseed oil) fatty acids. The heating maynow be continued with stirring to about 230 C. until a uniform, onephase system is obtained. The heating is continued until the desiredviscosity is secured. A product similar tothat of Example 2' isobtained.

Ezcample 6 The use of relatively small amounts of succinic acid or of amixture of succinic and maleic acids, say 3 to 10% of the weight of thephthalic, will usually be found to give markedly improved results, aswill be found by the following experiment.

Mols Grams Linoleic fatty acids 1.1 308 Phthalic acid 1.8 300 Succinicacid 0.13 Glycerol 3.3 300 are heated to 190 C. and kept at thistemperature for about one half hour. The temperature is then graduallyraised to about 230 C. and maintained there until a sample removed fromthe reaction mass is found to be soluble in toluol in substantially allproportions, as well as in fatty acids obtainableupon hydrolysis ofdrying and non-drying oils. There is thus obtained a resinous materialwhich is characterized particularly by baking pale when used with whitecoloring matter and by extraordinary adhesiveness upon smooth metallicsurfaces, including tin surfaces.

The following two examples illustrate the effect of employingsubstantially more than 1 mol.

of the dibasic aliphatic acid to each mol. of

phthalic acid.

Example 7 Mols Grams Linoleic fatty acids 1 280 Phthalic anhydride $4;49 succinic anhydride 67 Glycerol 1.1 101 On heating, two layers. formwhich persist even when the temperature of about 240 C. is reached andthe material, is constantly stirred. Finally, without forming a clear,uniform sys-, tem, flocculent matter begins to form and a solid layer ofgel forms on the bottom of the flask. This experiment shows that whenthe molecular proportion of succinic acid to phthalic acid issubstantially greater than 1:1, a homogeneous system cannot be obtainedif enough fatty oil acids are employed to make the product oil solublewhen the dibasic acid is all phthalic acid,

Example 8 Mols Grams Linoleic fatty acids 1 280 Phthalic anhydride M; 37succinic anhydride A 75 Glycero1 1.1 101 The ratio of succinic anhydrideto phthalic anhydride is 3 mols to 1 mol. I The same behavior isobserved as in Example 7, the two layers again persisting to the veryend, except that the lower layergels even sooner and the gel is morepronounced.

The resinous products obtained as hereinabove described in Examples 1 to6 are readily soluble in coal tar solvents and in mixtures of coal tarsolvents and petroleum distillates, such as mineral spirits, at least upto the proportions of solvent which yield commercial solutions.

In any of the above examples, malic and fumaric acids may be substitutedfor the succinic acid; succinic acid, or a mixture of succinic andmaleic acids, is however at present referred by me..

The high molecular weight fatty acids may be those obtained from drying,semi-drying and non-drying oils, such as linseed, China-wood,

soya bean,iperilla, sunflower, menhaden, cottonseed, castor, olive andother oils, and from fats.

I claim:

1. The method ofproducing in a single step a homogeneous, fusible resinsoluble in fatty oils which comprises reacting simultaneously glyceroland a plurality of acids consisting essentially of phthalic acid,succinic acid in a substantial amount up to approximately 1 mol. forevery mol. of phthalic acid, and an amount of acids obtainable onhydrolysis of a fatty triglyceride sufficient to make the productoil-soluble.

2. The method of producing in a single step a homogeneous, fusible resinsoluble in fatty oils which comprises reacting simultaneously glyceroland a plurality of acids consisting essentially of phthalic acid,succinic acid in a substantial amount up, to approximately 1 mol. forevery moi. of phthalic acid, and an amount of soya bean oil acidssufliclent to make the product oil-soluble.

3. The method of producing in a single step a homogeneous, fusible resinsoluble in fatty oils having incorporated therein a polybasic aliphaticacid, which comprises reacting simultaneously glycerol with a pluralityof non-resinous acids consisting essentially of phthalic acid, a mixtureof maleic and succinic acids in a substantial amount up to approximately1 mol. of both such acids for every mol. of phthalic'acid and an amountof acids obtained on hydrolysis of a fatty tri-glyceride suilicient tomake the product oilsoluble.

4. The method of producing in a single step a homogeneous fusible resinsoluble in fatty oils and having incorporated therein a polybasicallphatic acid which comprises reacting simultaneously glycerol witha'plurality of non-resinous acids consisting essentially of phthalicacid, a mixture of maleic and succinic acids comprising about 3 to 10%by weight of the phthalic acid, and an amount of acids obtained onhydrolysis of a fatty tri-glyceride suflicient to make the productoil-soluble.

5. The method of producing in a single step a homogeneous fusible resinsoluble in fatty oils and having incorporated therein a polybasicaliphatic acid which comprises reacting simultaneously glycerol with a.plurality of non-resinous acids consisting essentially of phthalic acid,a mixture of maleic and succinic acids comprising about 3 to 10% byweight of the phthalic acid,

, and an amount of acids obtained on hydrolysis of a drying fatty oilsuflicient to make the product oil-soluble.

6. The method of producing in a single step a homogeneous fusible resinsoluble in fatty oils and having incorporated therein a polybasicaliphatic ,acid which comprises reacting simultaneously glycerol with aplurality of non-resinous acids consisting essentially of phthalic acid,and succinic acid in an amount comprising about 8 to 10% by weight ofthe phthallc acid, and an amount of acids obtained on hydrolysis of afatty tri-glyceride sufficient to make the product oilsoluble.

7. The method as set forth in claim 1 wherein the glycerol and fattytriglyceride acids are present in approximately equimolecularproportions, the succinic acid being employed in an amount ranging fromapproximately 0.15 to 1 mol. for each moi. of phthalic acid, and theamount of glycerol being substantially equivalent to the total amount ofacids.

ISRAEL ROSENBLUM.

